The present invention pertains to the secondary containment of stored chemicals that are harmful to both the environment and living creatures. More particularly, the present invention relates to a zero ground disturbance dike apparatus for the secondary containment of stored harmful materials that does not require the drilling of postholes or the setting of support posts in concrete.
The storage of hazardous materials, such as petroleum contaminated process-water, industrial chemicals, liquid agricultural chemicals, and other corrosive chemicals in storage tanks are well known. Such tanks are designed and fabricated to prevent the uncontrolled release of these and other hazardous materials into the environment so as to reduce the risks associated with the pollution of the surrounding area and/or potential contamination of nearby ground water.
However, storage tanks have been known to occasionally accidentally leak or spill the entrapped hazardous material. In an attempt to minimize the potential harmful effects of such a leakage or spill, containment systems are often designed to incorporate both a primary storage containment vessel, such as a storage tank, and a secondary containment system. One form of secondary containment system that is often used with above ground containment systems is a dike apparatus.
In the past, dike apparatuses have been constructed from a variety of materials. Most dike apparatuses have been fabricated from earth, wood, and concrete. These apparatuses are often virtually permanent in both size and location. However, the construction of dike apparatuses from such materials, and their intended permanency, typically makes any attempt to subsequently expand these apparatus both labor intensive and expensive. Furthermore, when removed or vacated, such apparatuses often leave an indelible mark on the surrounding surface.
Dike apparatuses fabricated from metal are also well known in the art. These systems are often pre-fabricated before being transported to storage facilities for on-site assembly. The metallic walls of such apparatuses are typically bolted to support posts, with the support posts being secured into the surrounding ground. However, the metallic surfaces of these systems often prevent such dikes from being used in conjunction with the storage of materials that are highly reactive to metals, such as liquid fertilizers. Furthermore, the reliance on support posts that are secured-beneath the surrounding ground subjects these systems to damage related to frost heavage. Differential frost heavage typically results in the displacement of the support posts, and their attached wall sections, thus pulling the wall sections away from one another, and thereby potentially compromising the dike's seal of containment. The need to fix this reoccurring separation between the wall sections so as to maintain the integrity of the dike apparatus typically makes these systems costly to maintain.
U.S. Pat. No. 5,882,142 (“'142”) discloses a metal dike system that is designed to prevent damage due to frost heavage. The apparatus disclosed in U.S. Pat. No. '142 includes a plurality of wall sections that are attached to support posts, the support posts being secured in concrete that is located below the frost line. The support posts, which are preferably six to twelve feet long, include elongated apertures that receive the insertion of bolts that attach sections of the steel dike walls to the support posts. The elongation of the apertures is configured to permit the movement of the bolts along the apertures, thereby allowing the steel walls and support posts to move separately of each other in response to post displacement that is caused by differential frost heavage. Additionally, the steel walls are bolted to adjacent wall sections in an end-to-end arrangement so that, in instances of frost heavage, the movement of the posts will not affect the connection between the walls, and thereby prevent the dike seal from being compromised.
However, in order to secure support posts in concrete that is located below the frost line, as required by invention disclosed in U.S. Pat. No. '142, postholes must be drilled into the surrounding ground. In order to extend below the frost line, these postholes often have to be drilled up to depths of eight feet. Drilling to such depths can be both expensive and labor intensive, particularly in light of the fact that site conditions throughout the world vary greatly. For instance, in some areas, the presence of limestone or other rock strata makes drilling postholes very difficult and expensive. In other areas of the world, or during winter months, frozen ground increases the difficultly and expense of installation. Drilling to depths of up to eight feet also creates additional potential hazards, including the dangers associated with the drill hitting underground gas lines, electrical lines, and/or pipes. Furthermore, in some countries, such as Canada, local regulations prohibit ground penetrations of more than twelve inches on public lands. Additionally, because such storage facilities are often located in remote areas, transporting cement to set the support posts in the postholes, as required by the '142 patent, is expensive.
It is therefore an object of the present invention to provide an apparatus for the secondary containment of hazardous materials that may be accidentally released from a primary storage vessel.
It is a further object of the present invention to provide a zero ground disturbance system for the secondary containment of hazardous materials.
It is another object of the present invention to provide a secondary containment system that does not require the drilling of postholes for support posts.
A further object of the present invention is to provide a secondary containment system to control the accidental leakage or spillage of hazardous materials from a primary containment system that does not require the setting of support posts in concrete.
It is also on object of the present invention to provide a secondary containment system that complies with local regulations regarding limitations on ground penetration.
These and other desirable characteristics of the present invention will become apparent in view of the present specification, including the claims and drawings.